#include <stdio.h>

int main() {
    int score;
    
    printf("请输入学生成绩: ");
    scanf("%d", &score);
    
    if (score <= 100) {
	switch(score/10){
	    case 10:
		printf("成绩级别: A\n");
		break;
	    case 9:
		printf("成绩级别: A\n");
		break;
	    case 8:
		printf("成绩级别: B\n");
		break;
	    case 7:
		printf("成绩级别: C\n");
		break;
	    case 6:
		printf("成绩级别: D\n");
		break;
	    default:
	        printf("Sorry, you lost.\n");
	        break;
	}
    }

    else {
        printf("请输入0-100之间的分数。\n");
    }
    return 0;
}
